Asus Z87 -A/-C/-K

Hey
You can choose any mobo from these. There is no performance differences. You will get all z87 chipset mobos almost same performance. The difference will be minor which can't notice easily. You will get more features as well as you increase ur budget for mobo not much performance. So you can choose as u features need.
No need to worry.
I hope it helps.
Thank you.
 
Check here for easy compare:

http://promos.asus.com/us/Z87/comparison/

Note the VRM on the -C and -K if you intend overclocking, -A is a better long term bet for that due to 8 phase on VRM. 4 phase boards are best run at stock.
 

what is vrm?
 
VRM is a voltage regulator module ,
sometimes called PPM (processor
power module), is a buck converter
that provides a microprocessor the
appropriate supply voltage, converting
+5 V or +12 V to a much lower voltage
required by the CPU, allowing
processors with different supply
voltage to be mounted on the same
motherboard.